LAKEWOOD, Colo. – Confirmatory tests show four cows in a Colorado dairy herd have tested positive for bovine tuberculosis (TB).

The ongoing investigation by the Colorado Department of Agriculture and the United States Department of Agriculture began in March 2010 when internal lesions were discovered on a Southern Colorado cow at a slaughter facility. Subsequent tracing and testing has led to the discovery of the additional positive cattle.

Bovine tuberculosis causes internal lesions in infected animals. It is spread primarily by respiratory aerosols being exhaled by infected animals and can then be inhaled by animals or humans.

Meat from the infected animals did not enter the food chain; commercially sold milk is pasteurized, killing bacteria with heat, so there is no public health concern when consuming pasteurized dairy products.

Livestock owners with questions can contact the State Veterinarian’s Office at (303) 239-4161.